Brush-holder for dynamos and motors



(No Model.)

M. H. HATHAWAY.

BRUSH HOLDER FOR. DYNAMOS AND MOTORS.

NO. 478,104. Patented July 5, 1892.

ATTORNEYS UNITED STATES PATENT OEEICE.

MERRILL H. IIATHAIVAY, OF SPRINGFIELD, MASSACHUSETTS.

BRUSH-HOLDER FOR DYNAMOS AND MOTORS.

SPECIFICATION forming part of Letters Patent N 0. 478,104, dated July 5, 1892. Application iiled October 8, 1891. Serial No. 408,117. (No model.)

T0 @ZZ whom it' may concern,.-

Be it known that I, MERRILL H. HATHAWAY, of Springfield, in the county of Hampden and State of Massachusetts, have invented a new and useful Improvement in Brush -Holders for Dynamos and Motors, of which the following is a specification, reference being had t0 the accompanying' drawings, forming part thereof.

My invention relates to holders for the contact-brushesof dynamos and electric motors, and has for its object to provide a holder which, while simple and inexpensive in construction,will haveimproved means for holding and advancing the brush to compensate for wear of the latter and which can be readily applied to any of the various forms of dynamos and motors.

To this end my invention consists in the brush-holder constructed and operating as hereinafter fully described, and particularlyy pointed out in the claims.

Referring to the drawings, in which like letters designate like parts in the several iigures, Figure 1 is a View in perspective of the commutator of a dynamo or electric motor having applied thereto a brush-holder embodying my invention. Fig. 2 is a longitudinal section of the holder, taken upon line 2 2 of Fig. 3. Fig. 3 is a cross-section taken upon line 3 3 of Fig. 2. Fig. 4: is a detached view of the follower.

The letter a designates the rectangular body of the holder, which has its front end, or that end next to the conimutator, open and is provided witha removable bottom a', preferably sliding in ways in the two side pieces a2, as shown in Fig. 3. The rear end a3 of the holder is made integral with or is rigidly secured to said bottom and is provided at its center with an outwardly-projecting hub d4, which serves as a guide for the notched or toothed stem by which the follower-is advanced, which stem passes therethrough. Within said body is located the follower b, whose area is substantially that of the crosssectional area of the interior of the body, as shown in Fig. 3, whereby it is adapted to have a free sliding movement within the body without possibility of binding at any point. Said follower is preferably provided at each end thereof with the rearwardly-projecting` wings b', which assist in steadying its movement within the body, and is provided at its center with the rearwardly-projecting hub b?, which is preferably tubular in form, as shown, and which forms a socket to receive the coilspring c. Said spring c is preferably secured at its rear end to the notched or toothed stem d and at its front end bears against the follower, whereby it is caused to exert a constant pressure upon the latter toward the front end of the holder, the socket b2 preventing any material lateral deflection thereof. The stem d has its notches or teeth inclined rearwardly and is provided at its rear end with a suitable head d to enable it to be conveniently manipulated. I have herein shown said stem as consisting of a round rod and the hub a* at the rear end of the body as being tubular in form to form a guide therefor; but it will be understood that said stem and guide can be made of rectangular or other angular forni in cross-section, if desired. I have also shown herein a tube a5 secured to the front side of the end piece a3 and forming a continuation of the tubular guide a4 to assist in truly guiding the stem and the spring, said tube at its front end having a telescopic action within the hub b2 on the follower; but in practice said hub Z22 can itself be somewhat elongated and the intermediate tube Ct omitted, if desired. In connection with said follower, spring, and notched or toothed stem I employ a spring-actuated detent to engage the notches or teeth on the stem in such manner as to prevent rearward movement of the lat-ter, while permitting a free forward movement thereof. Various forms of detents for such purpose can be utilized; but I have shown and prefer to use one which is capable of performing the additional function of locling the removable bottom and rear end piece in position upon the body of the holder. Said detent (designated by the letter e) is pivoted between two ears a6, projecting from the upper side of the body a near its rear end, and has its long arm extending toward the front end of the body and terminating in a suitable finger-piece, as shown, and has its short arm curved downwardly and terminating at its extreme end in a bearingface e', adapted to engage the outer end of hub a4, and a beveled and transversely-curved IOO point e2, (see broken lines in Fig. 3,) adapted to engage the notches or teeth on the stem.v A coil-spring e3, bearing against the under` side of said detent at its front end, serves to normally retain its rear end in engagement with said hub and the stern. The bearingface e is of such width as to permit the detent to ride over the teeth on the stem as the latter is pushed inwardly without disengaging said face from the hub a".

It will be observed by reference to Fig. 2 that the follower is` adapted to be advanced to the extreme front end of the body a., and to avoid the possibility of its being projected entirely out of the body and lost I prefer to provide means for checking its movement at said extreme front end of the latter1 and as one example of such means I have shown said follower as having projecting laterally from the wings b thereof a stud or pin b3, which studs enter grooves a7 in the inner surface of theside pieces a2 of the body, said grooves extending from the rear end of said side pieces to a point just short of their front end, as shown by full and brokenv lines in Fig. 2.

The carbon or other brush f is inserted within the front end of the body'with its rear end against the follower and its front end projecting to the desired distance beyond the body, and when so inserted is securely held against all movement except one toward the front end of the holder in a plane parallel with the side pieces a2 of the latter. Its front end is therefore presented squarely to the pel riphery of the commutator g at all times and under all circumstances. The spring c presses the brush against lthe comm utator with a pressure which is constant and which is kept substantially uniform as the face of the brush wears away by pushing the stem d inwardly one or more notches at a time, as may seem necessary, the detent rigidly holding said stem in its adjusted position. It will be seen that for wear of the brush can be performed instantly and by the sense of touch alone, in which respect my device differs materially from such holders as employa threaded stem and a check-nut or other device for locking it against rotation. This feature of the holder devised by me is especially valuable and important when the holder is applied to motors for propelling street-cars and used in other similar situations-where access to the holders is obtained with difculty. The seating of the brush within the holder is such that it used until almost entirely Worn away, even though it be cracked or broken, and the usual frequent renewal of the brushes is therefore obviated. It will be observed, also, that there are n o exterior springs o1' other parts liable to be broken and thrown against the commutator to form a short circuit, as now frequently happens, all of the parts except the detent and its spring, which can have no breakingstrain exerted upon them, being completely housed within the body. The removable bottom and the parts mounted thereon can be readily withdrawn from the body without disturbing the connection of the latter with the dynamo or motor by simply depressing the front end of the detent and can be as readily replaced in the body.

I have shown the holder as being secured to a bracket-arm g of a dynamo or motor by means of a threaded bolt projecting laterally from the holder through said arm and receiving a lock-nut at its outer end; but it will be obvious that the holder, constructed as herein described is adapted to be applied to any of the various vforms of dynamos and motors in use and by any of the fastening means heretofore employed. The holder herein described,

moreover, is strong and durable in all ot' its parts, while being of simple and comparatively inexpensive construction.

It will be understood that, while I have herein described the holder as being provided with g a removable bottom, that term is used with f reference to the position in which the holder is illustrated in the drawings, and that should the holder be used in a reverse position to that shown said removable bottom would become a removable cover, it being wholly im- 1 material to the perfect operation of the holder 5 as described whether it be used in the one or the other position, the rear end piece in either case being formed integral with or rigidly secured to the removable part.

As hereinbefore stated, whileIhave shown a single detent-lever for engaging the notched 1 or toothed bar and also retaining the removable bottom and end piece upon the body, it is'entirely obvious that two separate detents for such purpose can be employed within the scope of my invention, if desired.

Having thus fully described my invention,

1. The brush-holder for dynamos and motors herein described, comprising, in combi- ;nation, a holder-body adapted to receive a ,carbon or other brush, a follower suitably guided within said body and adapted to bear against the rear end of said brush, a notched A or toothed stem guided at the rear end of said body for longitudinal movement, a springi actuated detent engaging the notches or teeth on said stem and adapted to hold the same against rearward movement, and aspring interposed between the front end of said stem j and said follower, substantially as described. will be held properly to its work and can be IOO what I claim, and desire to secure by Letters Patent, issuch movement of said sten-1 to compensate IIO IZO

2. The brushholder herein described, comprising, in combination, a holder-body which `is closed except at the front end thereof, a `follower guided within said body in such manner as to be capable of movement toward and away from said front end of the latter,a

notched or toothed stem passing freely y through the rear end of said body, a springactuated detent-lever pivotally secured to said body and engaging the notches or teeth on said stem, and a spring or springs interposed between said stem and the follower, substantially as set forth.

3. The brush-holder herein described, comprising, in eombin ation,a holder-body adapted to receive at its front end a carbon or other brush, a follower suitably guided wit-hin said body and adapted to bear against the rear end of the brush, said follower` being provided with a rearwardlyextending wing at each end thereof and witha rearwardly-projecting Ahub between said ends, a notched or toothed stem passing freely through the rear end of said body, a spring-actuated detent engaging the notches or teeth on said stem, and a coilspring located within the hub on said follower and engaging the end of said stem, substantially as set forth.

4. In a brush-holder, a holder-body provided with a removable bottom and having its rear end piece connected to or formed integral with said bottom, a follower guided within said body, a notched or toothed stein passing through said rear end piece for advancing the follower Within the body, a detent engaging the notches or teeth on said stem for holding the same against rearward movement, and means for locking said removable bottom and rear end piece upon the body, combined and operating substantially as described.

5. In a brush-holder, the combination, with the holder-body having the removable bottom and rear end piece, the follower Within said body, the notched or toothed stem passing through the rear end piece, and the interposed 35 spring, of a detent-lever pivotally connected to said body and having its rear end adapted to engage both said rear end piece and the notches or teeth on said stem and a spring normally holding said lever in such engage- 4o ment, substantially as described.

6. In a brush-holder, the combinatioinwith the holder-body, the follower guided therein, the notched or toothed stem,interposed spring, and spring-actuated detent engaging said stem, of a stop or stops located at the front end of said body for preventing the escape of the follower therefrom, substantially as described.

7. In a brush-holder, the combination, with 5o the body a, having the removable bottom a', and rear end piece CL3, having a rigid connec` tion with said bottom, said end piece having 

